Multi-row formula tool sum prior rows based on date

Question

Hello - looking for a way to sum values from previous rows based on a date range.  At the start of each month, I want to look back at the prior three months data based on the date.  So not just looking at the prior three rows of data, but looking at the date range.  If the prior two rows of data represent the previous two months but the prior third row of data is from six months back it would not be part of the sum.  Below is sample data.  Thanks for any help!

SPetrie · Answer

Glad that worked. Sorry I misunderstood the original ask. Try this multi-row

PrevMonths.yxmd

RCFranks · Answer

Thank you!  This solution worked for calculating based on prior month.  I was thinking with a multi-row formula tool, the calc could be dynamic and provide a value on each row based on the prior three months.  Similar to the screen grab below.  Is this possible?  Thanks again for the help!

SPetrie · Answer

One way of doing it

Find the maximum date for each Employee ID and then append that date to each of the rows for that employee.

Then filter out any records that are older than 4 months (current plus 3 previous) and filter out the current maximum month. Use another summarize on the values that are left to get the totals.

PrevMonths.yxmd